In recent years, a so-called micro electro mechanical system (MEMS) in which various semiconductor elements are mounted on a micro-processed Si substrate (silicon wafer) by applying large scale integration (LSI) manufacturing technology, is becoming popular. While fabricating such MEMS, an anisotropic etching using an alkaline solution is applied as a micro-processing method for a Si substrate. Due to the anisotropic etching, a fine recess can be precisely formed on the Si substrate for mounting a semiconductor element.
For example, in patent literature 1, a semiconductor device (LED (light-emitting diode) package) based on the above MEMS manufacturing technology is disclosed. In the semiconductor device, a horn having a bottom surface and a lateral surface is formed on a Si substrate, and an LED chip is mounted on the bottom surface of the horn. The LED chip is configured to be accommodated in the horn. Further, on the bottom surface and the lateral surface of the horn, an electrode is formed to be electrically connected to the LED chip. A film of Ti layer and a Cu layer formed on the Si substrate including the horn by a sputtering method or the like is patterned by photolithography and etching to form the electrode. After the electrode is formed, the LED chip is mounted on the bottom surface of the horn, and a sealing resin (resin mold) is filled in the horn, such that the semiconductor device is formed.
For example, in the semiconductor device disclosed in the patent literature 1, even in the case that a semiconductor element other than the LED chip is mounted, it can also be configured that the semiconductor element is accommodated in the horn and covered by the sealing resin. In the case that the semiconductor element generates more heat while being electrically connected, there is the following problem: the thermal conductivity of the sealing resin is lower than that of the Si substrate, and thus it is difficult to efficiently dissipate the heat generated from the semiconductor element to the outside.